Psychosis > Pre-pulse Inhibition
Description
In the pre-pulse inhibition (PPI) procedure, the rodent is placed in
a small chamber and exposed to a brief pulse of noise. The test is used
to assess the subject’s ability to "gate" or filter environmental
information. In the acoustic (startle model) of sensorimotor gating, a
weak acoustic stimulus (ie, the pre-pulse) decreases the reflexive
flinching response (startle) produced by a second, more intense,
stimulus (the pulse).
Purpose
Prepulse inhibition is a cross-species phenomenon (ie, it is present
in mammals ranging from mice to humans), yet it is relatively absent
among schizophrenic patients and, more recently discovered, among
patients with Alzheimer’s disease. The reduced ability to filter out
irrelevant auditory stimulation is a characteristic thought to
contribute to certain manifestations of these conditions including
inattention, distractibility, and cognitive deficits. The test is quite
useful for evaluating transgenic models of schizophrenia as well as to
screen potential antipsychotic drugs.